The cutting chain of a chain saw customarily runs on a guide bar which is affixed to and projects from the powerhead by which the chain is driven. The guide bar is usually "beaver-tail" shaped and is provided with a peripheral groove for retaining and guiding the cutting chain. The chain customarily has side links, the lower edges of which rest on the peripheral edge of the guide bar on opposite sides of the groove and center links having tangs which project beyond the lower edges of the side links and extend into the peripheral groove of the guide bar.
Guide bars may be of either solid or laminated construction. A solid guide bar is formed of a single steel plate, the peripheral edge of which is machined to provide a peripheral groove and chain-supporting edges on opposite sides of the groove. A laminated guide bar may be formed of three steel plates, the combined thickness of which is equal to the thickness of the desired guide bar. The two outer plates are of like size and shape while the middle plate which is sandwiched between the two outer plates is of similar shape but of smaller size so that when the plates are assembled the peripheral edge of the center plate is spaced inwardly from the peripheral edges of the two outer plates so as to provide a peripheral groove. The assembled plates are suitably united with one another for example by riveting. It is also known to make a laminated guide bar with only two plates which are spaced from one another by suitable spacers disposed between the plates. Alternatively, peripheral edge portions of the plates may be offset outwardly from the plane of the plate so as to provide a peripheral groove in the guide bar when the plates are assembled.